Abstract

A 245 cm long 210 kg extensively scarred male Bottlenose dolphin Tursiops truncatus stranded on Bolivar Peninsula, Galveston County, August 28, 2004 (29° 32.608 N, 095° 01.206 W). Necropsy revealed mild pulmonary angiomatosis, and studding of the left lung with nodular and diffuse densities, mostly clusters of nodules up to 3 mm diameter, with cysts, and areas of fibrosis and consolidation. The lung-associated lymph nodes were very large (up to 68 g).

A large (15.5 x 16 x 9.5 cm) firm, encapsulated solid, nodular fleshy white mass filled the right side of the mediastinum, in a location suggesting mediastinal/hilar lymph nodes, partly covered by serosa. The lymph nodes of the aortic arch and adjacent to the larynx were enlarged (6 x 4 x 3 cm), and the right adrenal was partly occupied by a similar masses measuring 3.5 x 2.5 x 3; an adjacent mass measured 2 x 2 x 2.5 cm. The laryngeal gland contained two 5 mm yellowish nodules. The initial impression was of metastatic neoplasia, possibly lymphoma, possibly sarcoma.

Microscopically, all lesions were similar cellular and fibrous focally necrotic granulomas, densely infiltrated by fungi. The fungus is characterized by lightly melanized round cells with thick cell walls, some cells 2-celled, rare muriform septation, occasional intercalary conidium or spore. Hyphae were absent. Morphology is compatible with a black yeast such as Sarcinomyces.

The 1722 g brain was grossly normal, except for a rough area on the left base and discoloration in the left basal ganglia. Microscopically, there was necrosis and infiltration by fungal hyphae, with a clear predilection for vessels, and characterized by melanized hyphae that are extremely variable in diameter and shape, sparsely septate, with irregular branching and a few vesicles. Some vesicles are thick-walled. Morphology is compatible with dematiaceous fungi such as Bipolaris. Molecular studies are pending.